Cars

Published on February 14th, 2016 | by Christopher Arcus

159

The Chevy Bolt — A Deeper Look

February 14th, 2016 by  

chevy_bolt_mules

The Bolt announcement has revealed significant details of the new Chevy Bolt electric vehicle. The pleasing combination of range, performance, and price are at a new level for electric vehicles.

With the current information, we can now compare to figures for the Sonic/Trax, the platform the Bolt shares, as well as the top-selling Nissan Leaf.

  • Trax = 167″L x 70″W x 65″H (Weight 3,048 lbs)
  • Bolt = 164″L x 69.5″W x 62.8″H (Weight 3,580 lbs)
  • Leaf = 175″L x 70″W x 61″H (Weight 3,256 lbs)

The Bolt is very short, even short compared to the Sonic/Trax, but is midway in height between the smaller Sonic and the mini SUV Trax, at almost 63 inches. The height and width make it have more frontal area than the Leaf.

The height adds to its interior volume. Cargo volume behind the rear seat is 16.9 cubic feet, though, a little less than the Leaf at 24 cubic feet. Passenger area specifications are fairly equal, with a bit more leg room in the rear for the Bolt. Keeping it short helps to keep the weight down, but it will be shown that the height and shortness make aerodynamic drag more difficult to manage.

Charging

The charging options are familiar, with slightly higher-power onboard charging at 7.2 kW compared to standard 6.6 kW, but that only results in about 25 miles per hour of charging. The DC fast charger is faster, but it takes 30 minutes for only 90 miles of charging, compared to Tesla’s 170 miles of charge in 30 minutes.

The Battery Pack

The 60 kWh battery pack, at 960 lbs (435 kg), has excellent specific energy, a bit less than Tesla’s 1200 lbs, 85 kWh pack.

Chevy Bolt battery

The specific energy numbers are:

  • Bolt 0.138 kWh/kg
  • Model S 0.156 kWh/kg

The Bolt pack is described as having 96 cell groups with 3 cells per group. At an average voltage per cell of 3.8 volt (V), the pack voltage consisting of 96 cells in series is about 365V. With a pack energy capacity of 60 kWh, and three cells in parallel per group, each cell has a rating of about 55 amp-hour. From the description of high nickel and manganese content and low thermal sensitivity, it is likely that this is a variation of the nickel-manganese-cobalt-oxide chemistry, NMC, an excellent choice for electric vehicle applications.

The cells are pouch type and fit neatly in a space-saving skateboard arrangement under the floor with a total 5 sections of 10 modules. At the back, the modules are stacked 2 high. This arrangement adds to the internal roominess and low center of gravity of the vehicle. The pack is also liquid cooled, which is likely to aid in long life, reliability, and improved performance over a wide range of conditions.

Range, Range, Range

GM won’t release range specifications until the EPA tests the vehicle, but says 200 miles of range. That appears likely for city driving. With the same 60 kWh battery capacity and a curb weight of only 3,580 lbs, compared to the Model S 60 at 4,407 lbs,
the Bolt should easily be able to travel more than 208 miles from full charge to full discharge in the city. Range at highway speeds is more important, because highway driving often matches the longest trips. For average speeds and travel distances between rest stops, 3-hour driving time for 200 miles of range means average speeds of 65 to 70 mph. The highway range must be measured by those standards.

At those speeds, aerodynamic drag dominates.

battery Wh:mile

Whpermilevsspeed

Aerodynamics

To determine aerodynamic drag, we have to look at the effective frontal area, the product of coefficient of aerodynamic drag, Cd, and frontal area. For comparison, the Model S is 77.3 inches wide by 56.5 inches tall, with mirrors folded.

The Bolt is 69.5 inches wide by 62.8 inches tall.

Frontal Area

  • Model S — 4,367 square inches
  • Bolt — 4,365 square inches

The two cars have virtually identical frontal area. The Model S has a Cd of 0.24. The Bolt designers did their best to lower Cd; however, it’s unlikely they achieved such a low Cd. To see why, we need to look at airflow. The goal of aerodynamics is to achieve the lowest drag. The subject is deep, fraught with details, and full of pitfalls for the educated, experienced, and neophyte alike. However, there are some principles that apply.

A member of the winning team for the tandem category in a competition once told me these words, “move the air only once, and put it back gently.” In aerodynamic terms, no sharp increases or decreases in pressure. The goal is “laminar flow,” the smooth flow of air around the object, without turbulence. The ideal shape is a teardrop, with a rounded front, and tapered rear. The Bolt shape has a smooth front with no sudden changes, good for aerodynamics, and a tail described as a kammback, shaped like a bullet. There is some tapering, but the abrupt rear end stops before the shape has reduced a lot. Some effort has been made to improve it with the rear spoiler extending the roof further to the rear. Below is a video of how this behaves in a wind tunnel. The upper and lower airflows are shown in two different colors.

If you look carefully, you can see two whorls or vortices at the rear that rotate in opposite directions, one on top, and one on the bottom.

Now, let’s take a look at another design, the boat tail. The boat tail slices off the rear of the teardrop shape farther toward the rear than the kammback.

Notice how much smaller the vortices are and how the upper vortex is almost eliminated. As a rule of thumb, the larger the vortices and the more upper and lower vortices, the higher the drag. The boat tail design results in a lower drag coefficient. A glance at the Model S reveals that it has a boat tail appearance. The kammback of the Bolt is likely to result in higher Cd and drag.

The Leaf, with a similar kammback, achieves a Cd of 0.28. There are many other details to aerodynamics, but the overall shape is a good indicator of performance.

The Model S range vs speed graph shows the range is just around the 200 mile mark at the speeds of interest. From those facts, it looks like the Bolt will have just under 200 mile range at the highway speeds of interest. The large frontal area and high Cd of the Bolt mean that the same size battery pack as the Model S 60, will not carry it as far at highway speeds. If, instead, the frontal area was lower and the Cd was also, the size of the battery pack could be decreased or the range increased.

It’s no secret that GM wants this early introduction to compete with the upcoming Tesla Model 3 in March. It might be speculated that a Model 3 with a 20% reduction in frontal area, and with a similar sedan shape and Cd, might result in at least a 20% lighter car with 20% less frontal area. If that is the case, the battery might also be 20% smaller, or about 50 kWh, resulting in lower cost. Coincidentally, a 20% lighter car than the Model S would be 3,520 lbs.

Performance

The claimed figure of 7 seconds 0–60 mph matches the battery and motor capability. The motor, battery, and controller determine the acceleration. With the large battery pack and about 165 amp-hours at about 365V, there is ample power available from the battery. An NMC battery should be easily capable of 3C performance, leading to power ratings of 200 horsepower, consistent with the motor rating. Doubtless, the designers decided to take advantage of this capability. That kind of performance will win many converts, if they don’t mind the package being more family friendly. The heavily tapered front end does impart a sporty flavor.

What’s Not to Like?

This is the first affordable, 200-mile range, electric vehicle on the market. That makes it a unique item of value. As the first of its kind, with a price in the mid $30,000s, good interior space, zippy acceleration, and long range, it promises to be a popular item. It’s hitting a lot of wants and needs. It could be used for medium trips up to ~200 miles under good conditions. Even with slightly higher aerodynamic drag, the large battery makes for long range. Although it does not charge as fast as a Model S, only 90 miles in a half hour, about a 1 hour stop every 3 hours (~200 miles), it could still extend travel relatively long distances in decent time. While not as pleasing as the faster-charging and longer-range Model S, it does have a lower initial entry price. The biggest difficulty now is the lack of an extensive SAE DC fast-charger cross-country network. That is likely to change with the introduction of the Bolt, spurring third-party chargers to expand.





Check out our new 93-page EV report, based on over 2,000 surveys collected from EV drivers in 49 of 50 US states, 26 European countries, and 9 Canadian provinces.

Tags: , , , , , , , , , , , , , , , , , , ,


About the Author

has studied wind, electric vehicles, and environmental issues. An electrical engineer familiar with power and electronics, he has participated in the Automotive X Prize contest. He is an avid writer, specializing in electric vehicles, batteries, and wind energy.



  • Michael Wallis

    But will it have CarPlay??

  • ROBwithaB

    The battery in your smartphone is not the same as the battery in your car. And the graph you provided here actually contradicts your point, if you read it correctly and understand the context.

    Please see the reply I posted to your wife/sock account/alter ego Sandra Allen above, who provided me with exactly the same links as “proof”.

  • ROBwithaB

    Those are very generic sources of information you provided, and not really relevant here, because…..

    Here’s my understanding of the situation:
    (I don’t claim to be an expert, but I have been trying to educate myself for the last couple for years to understand this better.)

    In real life, the degradation profile of a battery is very dependent on its specific chemistry, of both the electrolyte and the electrodes.
    There’s no such thing as a “standard lithium ion battery”. There is a staggering array of different options available to a battery designer, and these will be tweaked according to what parameters are to be optimised, e.g. energy density, cycle life, cost, calendar life, C rates, optimal charge/discharge range, etc (Always going to be some compromises, as other here have pointed out. You can’t have a “perfect” battery. Decide which qualities are important to you, and design for those.)
    As a greater understanding develops around the actual causes of battery degradation (dendritic growth, intercalation errors, etc) on a microscopic level, it becomes easier to make subtle changes to the chemistry that have profound effects on the rate of the reactions involved.
    (I don’t pretend to actually understand all the chemistry myself, but there’s lots of stuff online if you’re curious.)

    The MOST important factor, however, is probably temperature. The processes that lead to degradation are simply chemical reactions. All chemical reactions are temperature dependent (and time dependent).
    In my original post, I asserted that fast charging will not significantly degrade the battery as long as the process is thermally managed. Especially so if the battery was designed to allow for high C rates.

    Because chemical reactions are also time dependent, it is actually possible that fast charging can REDUCE battery degradation, because the reaction simply has less time to occur. This is something that has been explained quite eloquently by, amongst others, Prof Dahn of Dalhousie.
    The same Prof Dahn who is probably the world’s leading expert on battery degradation. Who has come up with innovative ways to simulate long term battery degradation very accurately and repeatably.
    The same Prof Dahn who now works for Tesla.

    The degradation from rapid charging can be minimised in a number of ways. The first would be to spread the load over a large number of cells, which is one of the reasons Tesla opted for the “many-little-cylinders” layout, I suspect. The next would be to keep temperatures constant. Ditto. Minimise swelling/distortion. Ditto.
    And then make sure you have the right chemistry. (I don’t know enough to comment definitively on the various options.)
    But Tesla is basically a battery company. They would not be offering an eight year warranty if they weren’t VERY sure that they would be able to honour it.

    Here’s a quick primer from Autoblog:
    http://www.autoblog.com/2014/10/06/fast-charging-your-ev-might-not-be-as-bad-as-predicted/
    And here’s a link to the article in “Nature”: http://www.nature.com/nmat/journal/v13/n12/full/nmat4084.html
    I can send you some additional links to more technical stuff if you’re interested….

  • Zero_X_Rider

    A boat tail adds 900 pounds? What am I missing?

  • nakedChimp

    imperial units, really?

  • eveee

    Check my comment below. A number of assumptions are incorrect. Those curves vary with battery chemistry and are not fixed. Also, the Tesla pack is running at around 1C on the SuperCharger. That would put it on that upper curve.
    Hardly cause for alarm. But even at that, we don’t know if that curve is the one for the Tesla pack.

  • tech01xpert

    IfSlashWhen, try reading battery lifecycle research papers… your education is very lacking.

  • eveee

    What is the charge rate of the cells of a 90kwhr Tesla battery with a Tesla Supercharger?

  • Tim

    Ummm … discharge rates don’t go up when supercharging, so let’s cut your chart in half right there. Now, supercharging is supposed to be used sparingly or you get a letter and a hairy eyeball from everybody cause you’re a cheap bastard. Understand? So, no, as an EE myself, I think you’re bad at analyzing this situation. Don’t worry though, they’re not your warranties.

    • IfSlashWhen

      Battery degradation from charge rate or discharge rate is symmetrical (increased charge rate degrades a cell just as much increased discharge rate), as an EE with a specialty in battery chemistry, you’ll undoubtedly know this.

      GM can’t rely on letters and “hairy eyeballs”, they have to make sure that it simply isn’t possible for a user to degrade the battery under the terms of the warranty.

      • Tim

        the future may bring tiered battery warranties involving fast charging amounts just like lease agreements and warranties do now especially since how many miles you quick charge a battery can be recorded.

      • eveee

        That battery degradation chart is not the same for every battery. A low C rate battery may have a different chart and probably does not tolerate higher C rates well. The assumption that a lower C rate battery has longer life because it charges slower is wrong. C rate is determined in part by internal series resistance. That causes heating and voltage drop that does not charge the battery. Heat leads to inefficiency and shorter life.
        An A123 battery could probably charge to 5C its whole life an d only degrade as much as a lower C rate battery like the Tesla does at 1C. A123 batteries have proven capable of 25C charging. Some of the longest cycle life batteries in the world are lithium titanate. These have very low internal resistance and can discharge at 25C comfortably. Their cycle life is in the 10s of thousands.

    • eveee

      Check the actual Telsa supercharging C rate. Its about 0.8 to 1.2. Now look at the chart. See why Supercharging doesnt seriously degrade the battery? At 1C or below, the cycle life is not much affected.
      Suppose you had a 90kwhr battery, with a range of over 265 miles and charged it 80% every time with a SuperCharger. Now the shown curve does not necessarily apply to a Tesla battery. But if it did, we can calculate (approximately), that the car could travel 0.8 x 265 x 500 = 132,000 miles before its capacity degraded to 80% of original.
      Its all well and good to say fast charging degrades battery life. But how much ?
      Engineering.

  • ROBwithaB

    Nice tutorial on the basics of aerodynamics.

    I’m not a fan of what people like to call “aggressive” styling. Lots of pleats and creases in the bodywork, which only serve to increase drag.

    My understanding is that GM wanted to make the Bolt look like a “regular” car. That might well be the way to go to increase consumer acceptance.
    But I’m pessimistic about the real-world range for the vehicle. At highway speeds, this thing is going to be swishing a lot of air about.

  • Ed

    I saw the Bolt at Las Vegas: fully tooled and looking really great. Now….how do we convince GM that having a 200 mile range is not of great value if there is no charging network to let it go city-to-city. Some would suggest that the failure to build a charging network – not currently required by EPA or CARB – tells us that to GM the Bolt is just a compliance vehicle.

    • Steve Grinwis

      So, GM rolls out a 200 mile range EV nationwide, and it’s lumped into the same category as a Honda Fit EV?

      Talk about moving the goal posts…

      • Ed

        We just watched GM screw up the Cadillac ELR in market positioning, but in fairness, I should wait to see how GM promotes the Bolt before I judge. Sorry.

        • bwollsch

          GM’s marketing guy was interviewed and he said they were not going to do an ad campaign. I guess they expect word of mouth to push sales the way Tesla is doing. I think that’s a mistake, but if the do advertise, I think the question of charging stations will come up and the same marketing guy says that GM will not build out a charging network, they expect someone else to do that.

          I can’t tell if they don’t want to cannibalize ICE sales or they just want to say “see I told you no one wants an electric car.”

          • Ed

            Well…..they MUST sell enough to keep from buying credits from Tesla, so they will not advertise if they are hitting their minimum sales goals. If not, they will start ramping up the incentives in August, and maybe even run local ads in September or October until they are sure to meet their annual sales requirement.
            It is a compliance car! Nuts….I was hoping they would be serious about EVs since Mary took the helm.

          • Steve Grinwis

            Compliance cars aren’t offered outside of the CARB states.

          • Ed

            Yes, and I am pretty sure GM is planning only to sell in CARB states, markets that represent only about 25% of US cars sold.

          • Steve Grinwis
          • Ed

            My interpretation is different, so let’s just wait and see. I stand by my comment as a prediction, however.

          • Steve Grinwis

            I don’t feel there is room for misinterpretation, but whatever.

          • ROBwithaB

            From what I’ve heard, it seems like there is a big difference between “technically available in all fifty states” and “actually available on the floor right now of a dealership within convenient driving distance of your home, with a salesman on hand who knowledgeable and enthusiastic enough to make sure you leave the showroom in one.”

          • Steve Grinwis

            By this definition, a Ferrari is a compliance car…

          • ROBwithaB

            I don’t think Ferrari has ever made noises about “scaling up to hundreds of thousands of vehicles a year, if the demand is there”.

            I’m hoping GM is serious about this, but there seem to be some mixed signals coming out. Like that one crazy ex-girlfriend. Woops. Sorry, different conversation.

          • Gregory Suhr

            I believe Mary Barra said at the unveiling at CES that it was going to be a 50 state car.

      • Garrick Staples

        To the buyer, if the bolt doesn’t quick charge, then it’s still just a city car. It’s not fundamentally different than a Leaf.

        Whether the inability to quick charge is by design or lack of infrastructure makes no difference to the buyer.

        The tesla 3 becomes a very clear winner because of quick charge alone.

    • IfSlashWhen

      Chevy believes that a significant market is represented by 2 vehicle households who will either have a ICE for long range, or (ideally from Chevy’v viewpoint have a Volt as the other car 🙂

      • Ed

        I have not read that from GM, but likely true. Thanks.

        • IfSlashWhen

          That said, they are definitely trying to avoid investing in infrastructure, and trying to ride on the coat-tails of others who they hope will spend to deploy CCS.

          Tesla has been very smart in creatimg a proprietary standard; in fact, that is what will save the company from being crushed by the established auto makers. Elon is a very smart dude.

          • Bob_Wallace

            Not proprietary. Tesla has offered to let other car companies use its charging system. But they have to use the system as it is, a prepaid DC system.

            Tesla has not offered to create a second pay per use system for other companies. If GM or other companies want pay per use then they have a choice. They can set one up or wait to see if someone else does it for them.

            And they will have to build EVs that can be rapidly charged. The Bolt cannot.

          • IfSlashWhen

            First, the Tesla system *is* proprietary, it is not an interoperable standard like CCS (if it were a standard Tesla could not dictate terms on how they’ll share it).

            Secondly the Bolt utilizes SAE-CCS (which is a standard) for fast charging to 80% in 30 minutes.

          • Steve Grinwis

            WHile the bolt does use SAE-CCS, it won’t fast charge in 30 minutes. It’ll do 80% in more like an hour, full charge in 90 minutes. This is a limitation of the car, not the charging standard, and I have no idea why the car is limited in this way.

          • IfSlashWhen

            The reason is that Chevy doesn’t want to have warranty claims on batteries (fast charging degrades battery life significantly), so they limit it in software. You’ll likely be able to hack the software to bypass the restriction, if you are willing to forgo the loss of warranty coverage,

          • Bob_Wallace

            Oh, come on.

            If you take a Sawzall to the roof you can make it a convertible.

          • IfSlashWhen

            It’s just software; it is easy to modify (no harder than jailbreaking your iPhone). You won’t be able to get your battery replaced if it dies though, if you change it.

            Tesla is going to start to have major expenses in battery replacements starting this year because of battery degradation from supercharger use, but like I said, the strategic advantage they obtain allows them to stay in business (the established auto makers don’t need to do things like this to stay alive, Tesla does).

          • ROBwithaB

            Do you have specific links to back up your assertion that fast charging hastens battery degradation?
            From what I understand, the opposite is actually true, as long as the process is “thermally managed”.

          • Matt

            That is the point, if you have to void the warranty to get fast charging, then for 99% or people it does NOT have fast charging.

          • IfSlashWhen

            You don’t have to void the warranty to get fast charging, you only need to void the warranty to get *faster* charging. The chemistry of Li-ion is not magically different in the Tesla batteries, they are simply sacrificing back-end profits for the ability to stay alive. Without clear advantages (to the consumer) over the established makers, Tesla would be crushed by their marketing and scale. They can’t afford to take the loss *now* (i.e. drop the price or sacrifice their supercharge advantage), but they clearly believe they’ll be able to afford to take the hit 5 years from now.

          • Joe Viocoe

            There are several electrical engineers on this forum. You haven’t convinced any of them that Fast Charging significantly degrades the battery. The simplest explanation is that you are misinterpreting some old rules of thumb as a law that is applicable to modern Li-Ion batteries.

            Fast Charging doesn’t even kill Nissan Leaf batteries… which are air cooled. GM and Tesla have superior battery cooling, and certainly won’t be affected by Fast Charging.

            http://insideevs.com/idaho-national-laboratory-dc-quick-charging-nissan-leaf-doesnt-kill-battery/

          • Mike

            Do you have any charts or sources that can back up your claim of systemic battery degradation from supercharger use? If so, please provide them so I can have a look. Thanks. Cheers. Mike.

          • tech01xpert

            IfSlashWhen, do you have a source for your accusations? I suspect not, but hey… it’s not like Tesla battery data isn’t reported by lots of owners all the time that refutes your groundless statement about Supercharging.

            You seem to know very little about DC charging and EVs in general.

          • Tim

            Nice image! Harold and Maude

          • Bob_Wallace

            One of my favorite movies.

          • eveee

            You thinking what Im thinking? 2:29
            https://www.youtube.com/watch?v=vM4O9-HTvL8

          • Steve Grinwis

            Yes, It’s limited in software, but we don’t know why it’s limited in software. It could be warranty claims on batteries. It could be the cooling system isn’t good enough, if could be they cheaped out on cables to the battery pack. It could be a dozen different things.

            It’s possible that the next year, charging will be faster, once they’re more confident in the batteries, or something. They did that with the Volt, where the battery capacity increased with a software change…

          • Carl Raymond S

            ” It could be a dozen different things.”

            One of which is that GM don’t want to put a car on the market that is better in every way than the rest of their product offering.

            Not saying that is the reason – just saying that it could be.

          • Steve Grinwis

            Ya, perhaps.. But that didn’t stop Kia, Nissan, Mitsubishi, or even Chevy (with the Spark EV) from offering good fast charging on their EVs…

          • Carl Raymond S

            Are you saying that those cars have good fast charging?
            Sorry, I’m confused.
            Tesla announced their supercharger network in September 2012. So the competition has had more than three years to work out how it’s done. Musk has spoken openly about the natural cadence of a road trip – 6 parts driving, 1 part resting. How can the traditional automakers not ‘get it’? Either Tesla technology is far superior, or Tesla are the only one genuinely trying. Either way, the ICEV industry looks backward.

          • Steve Grinwis

            I mean these other cars are physically capable of doing an 80% charge in 30 minutes. I’m not talking about the devices providing the power.

          • Frank

            I remember seeing a new SAE 150kw charging standard. Now you just need chargers, and some cars that can accept that much power. Awesome sounding vaporware.

          • vensonata

            Methinks it is the battery chemistry of manganese. That is what Tesla used in the 7 kwh powerwall because it has higher cycle life (5000), but it won’t handle the rapid charge/discharge as well as the lower lifecycle Tesla car batteries (1200-1500). So Gm has gone for higher lifecycle but lower charging speed. Choices, choices, that is the gamble in business.

          • Steve Grinwis

            This is the best explanation I’ve heard. It plays into my view that GM is being super cautious.

            In the end, if I have to chose between a battery that lasts 20 years, and doesn’t quick charge well, or a car that quick charges well, but lasts 8 years, I *think* I’d take the former. I don’t really drive distance trips with my commuter car anyways… I might not be the typical electric car driver though? Who knows. Hopefully someone at GM knows what they’re doing.

          • vensonata

            Yes, the Volt battery as well seems to be reliable. I think they don’t want that early Leaf battery in Arizona scenario happening. GM’s research might have uncovered a customer worry with battery longevity as a greater concern than the charging time.

          • bwollsch

            Chargers too. DCFC only outputs at 50kw/hr. Tesla SC outputs at 135kw/hr.

          • Steve Grinwis

            Please see this SAE DCFC charger, that charges at 100 kW.

            http://insideevs.com/kia-installs-first-100-kw-chademo-dc-fast-chargers-europe/

            It’s actually faster than the first super chargers.

          • bwollsch

            Excellent. I didn’t know that. But they are only available in Europe right now. Any word on whether KIA will install them in the US, or allow someone else to buy and install them?

          • eveee

            Wouldn’t it need the 100kw SAE charger to fast charge in 30 minutes? Is GM just saying it because there are no 100kw SAE chargers around and they are quoting the 50kw rate?

          • Steve Grinwis

            The car still controls how fast the charge comes in. Even if the charger was capable of providing 200 kW, it would still take 90 minutes to charge. Otherwise, GM would install a single 100 kW charger, or use Kia’s existing 100 kW chargers, and quote the 30 minute charge rate…

          • eveee

            This goes right back to which is doing the limiting and we don’t know. But at 50kw, the 60kwhr battery takes over an hour to charge. Could it be that GM decided not to advertise it charging at a higher rate because customers would cry foul because they could find nary a 100kw SAE charger?
            Here is an article about 100kw DCFC installed by Kia. It lowers the charge time from 33 minutes to 25.

            “compared to the more common 50 kW brings charging time of Kia Soul EV from empty to 80% from 33 to 25 minutes. Battery pack is 27 kWh.”

            Clearly that batter pack can only charge a little over 2C. Going to 100kw doesn’t help that one much.

            Outside of a Kia dealer (kinda useless to a GM customer) where is a Bolt customer going to find a 100kw SAE charger?

            http://insideevs.com/kia-installs-first-100-kw-chademo-dc-fast-chargers-europe/

          • Joe Viocoe

            I wish popular charging station locator apps would let you filter out based on KW.
            The CCS standard looks like a impressively fast rollout on a map compared to Tesla… but it doesn’t take into account that each CCS station likely only has a single 25 KW station. While each Supercharger station has about 8 stalls with 120 KW each.

          • eveee

            Yeah. I hate that. 25kw is a sip of water in the desert. I need a hose going long distance filling up a 60kwhr battery.

          • eveee

            The car does control the charger to determine how much the charge comes in, true. But we still don’t now which limits the Bolt. On the other hand, if we hooked up a Bolt to a 100kw charger, we would know right away which was limiting charge rate. I was just saying with a charger like the SAE 25kw or 50kw, we still couldn’t be sure.
            But I think I see where you are going with this. Check me if I get your drift. Are you saying that if GM says thats their charge rate, you think that thats the way they have designed it, according to the battery limitations or the conservative design and guesses of the GM designers, not the limitations of SAE chargers?
            I still would like to know for sure if its a battery limitation. If it is, it means either LGChem has not been as successful as Panasonic in squeezing performance out of their NMC cells, or GM is unsure of itself without battery data and is over conservative. Either way, if that is really the battery limit, the pack performance is just not up to snuff.
            IMO, making the pack last 500,000 miles in city driving while lacking the desired long distance charging times is not a practical idea.

          • Bob_Wallace

            “making the pack last 500,000 miles in city driving while lacking the desired long distance charging times is not a practical idea”

            If practical means unwise. I would guess that less than 1% of new car buyers would be impressed by batteries lasting longer than 200k, 250k. I would guess that almost no new car buyers plan on driving that car into the ground. If they’ve got money to buy a new car then they’re likely to expect they’ll have the money to buy a new car before this one reaches 150k miles.

            On the other hand I expect most new car buyers would be a least a little bit swayed by the ability or lack of ability for the car to be used for long distance driving. If nothing else most would realize that the resale value is likely to be less if function is limited.

          • Steve Grinwis

            See, I’m not convinced that people are going to be that much more upset about a 60 minute stop instead of a 45 minute stop, like you seem to think. Normal operation isn’t long distance travelling.

            However, when your EV with 120k on it, is worthless because “the battery is almost ready to be junked” that could make it not worthwhile. Time will tell.

          • Steve Grinwis

            That is what I’m saying yes. And I’m still somewhat baffled by the charge time as well. Literally every other EV on the market fast charges in 30 minutes.

          • eveee

            Whichever one of us finds out first, I am sure either of us will comment.:)
            I hate it when something like that bothers me. I am dying to know, but I just can’t find out for sure and have to wait.

          • Bob_Wallace

            Yes, the Tesla system is proprietary. Proprietary means privately owned.

            But Tesla has not said that other car companies cannot use their system. Tesla is clearly open to allowing other car companies to use their system.

            Steve answered the 80% in a half hour part. Unless you have different information it’s 80% in an hour.

          • IfSlashWhen

            It is 80% in an hour without losing your warranty. Tesla does not invalidate your warranty for charging to 80% in 30 minutes. That is a clear advantage for Tesla (so long as they honor the warranty claims that start to happen in volume after 5 years – as the battery won’t last 8 years with heavy fast charging).

          • Bob_Wallace

            You do not make a valid argument when you start talking about modifying a car, especially warranty voiding modifications.

            Let’s keep it to what you get when you sign the papers.

          • IfSlashWhen

            I grant that this is an advantage for Tesla. It doesn’t change the science however; your Tesla battery will still die early, it is just that (hopefully) they’ll honor the warranty and you’ll get the benefit of fast charging without paying the price.

          • Bob_Wallace

            Tesla has stated that their batteries should last for 200,000 miles and that reasonable use of rapid charging will not harm their batteries.

            You do realize that Tesla batteries are liquid cooled, don’t you?

          • Matt

            This is started to sound like a religious debate. There are many who will not believe the Tesla claim until after there are many cars passed the 200k mark. And in fact lots or cars in the 150k-250k range is when real life will show us what happen with them. Of course with improving tech and lessoned learned, next years EV will be better than those create 5 years ago.

          • ROBwithaB

            Exactly. Knowing that some really high-mileage drivers purchased Supercharger-capable Teslas specifically for the “free gas”, we’re likely to find out quite soon.
            Not unusual for sales reps, regional franchise managers, airport limos etc, to average 200-300 km per day, for perhaps 300 days a year. The first heavily supercharged cars might well be approaching the 200k mile mark already.

            We’ll know soon enough if this is a valid concern or unnecessary sky fallingness. I suspect the latter.

          • IfSlashWhen

            Of course I realize that Tesla batteries are liquid cooled (so are the batteries in my Volt, and they are also liquid cooled in the Bolt). Please review the technical information below which shows that cell degradation as a result of fast charging. The degradation (in this case) is not related to temperature.

            Tesla has staked the company on a proprietary supercharging network, it is a brilliant move, even if it costs them down the road. Of course Tesla won’t publicly announce that they know the batteries will degrade early.

          • Bob_Wallace

            Tesla has been running their batteries in test for years. I suspect they know how the batteries are going to hold up. And publicly traded companies aren’t wise to mislead buyers.

          • IfSlashWhen

            Of course, they know how they’ll hold up. Again, Li-ion chemistry fundamentally degrades when charged at higher voltage. This is a physical limitation.

            Tesla knows they’ll have to replace batteries on warranty, but they are prepared to pay that price, since they are the disruptor, and they don’t really have a choice.

            The important thing to realize as a consumer, is that your Tesla battery will not miraculously last longer than a Chevy battery in the presence of fast charging. You need to know you are relying on them to honor the warranty (which I am confident they will). If fast charging is that important to you, then, by all means, buy a Tesla because they are the only company currently offering to indemnify you against the loss of the battery while charging it to 80% in 30 minutes.

          • Peter Voight

            Tesla’s warranty is 200,000 miles. That’s about 70MWh, throughput, so not a problem for an 85kWh battery.

            85kWh, is the size of the bucket, that’s all.
            Even if depth of discharge were 100%, then <850 cycles.
            A big battery where frequent top-up is employed, should easily meet the warranty. Even at the fastest rate, the charging current of each cell is around 3A, so 1C.

            Throughput is a more useful measure than cycles. Battery life is not all about 'degradation'. Capacity can remain, but increasing internal resistance prevents access to it.

            200 miles range may help to offset 'range anxiety' but produces 'charger anxiety'. So a lot of high-powered charging stations are built to address that problem. The Bolt is aimed at a different market, where short journeys mean home charging is possible. Perhaps faster charging will be later.

          • eveee

            How early?

          • ROBwithaB

            You’re repeating a statement about battery degradation as if you have specific information to back it up. I am not aware of any such information. In fact, the opposite seems to be true, in that the first batteries on the Roadster are actually demonstrating LESS degradation than expected.

          • This recent NREL study shows an insignificant loss of 2.6% in battery capacity for a typical fast charging frequency vs only level 2 charging. i.e. under typical use conditions, fast charging will not significantly degrade your battery. http://www.nrel.gov/docs/fy15osti/63700.pdf

          • eveee

            Yes. There are many reasons for this with the Model S. Not the least of which is that is a very large pack and has excellent thermal regulation.

          • Tim

            I’m thinking that supercharging an average of 5 times per year for those loooong trips more than 250 miles in one day and the rest at home will make NO appreciable difference in overall battery wear. Those that supercharge twice a week because they bought a $100k car but are too cheap to buy the electricity at home will probably get a letter from Elon. Either way, I think Tesla does OK with this decision warranty wise.

          • IfSlashWhen

            Tim, you’re correct that if you use a supercharger only 4 or 5 times per year, that the degradation over 5 years will be minimal (this is how Tesla hopes you will actually use it).

            A letter from Elon asking one to stop supercharging so much has no legal weight however. GM tends to think about these things in dry legal terms, and they would not expect that a letter from Mary Barra, pleading that you stop using high voltage DC charging so much, would yield any significant reduction in this abuse; hence GM would be very likely to limit the charge rate in software so that they don’t have warranty liabilities 5 years down the road (if you mod the software you relieve them of their liability).

            This is just to explain why Chevy does things different than Tesla from a business viewpoint.

            If you are an environmentalist, you should probably make your battery last as long as possible, since disposing of Li-ion batteries is not without environmental cost.

          • Tim

            You are very correct to point out that a small number of $100k car owners are going to act very differently than a large number of $30k car owners and that the car companies need to take that into consideration!

          • IfSlashWhen

            Exactly. Hence, the reason that Tesla can do things differently (from a business POV) than GM. There isn’t a technology difference, just different business situations.

          • eveee

            Thats right. And thats about how it looks like things are turning out.
            http://cleantechnica.com/2015/05/18/battery-degradation-level-in-tesla-model-s-only-5-after-30000-miles/

            The formula is this. Make the battery big enough so that an average daily use is a small fraction of the depth of discharge and the battery never gets anywhere near fully discharged, Added to that, make it so that city short driving never charges to 100%. The data shows that if you do that and no DCFC, you get cycle life equivalent to much more than 10 years and 100,000 miles. IMO, a Model S could go 200k before needing a new pack or reducing to 80% of initial capacity like that.
            A bit less if its DCFC a lot. Only a little less if its DCFC infrequently.

            The Tesla pack is very well regulated and maintained at good temperature conditions for longest life. By the time you need another pack, replacement costs will be much lower or packs will be much bigger or both.

          • Frank

            Which is a good thing, because it won’t rust, and if the motor got the right amount of greese in it, it may go a million miles. And it won’t even be spewing noxious fumes from the engine running rough.

          • eveee

            Yes. I don’t know why people don’t get that. EVs not only emit less carbon and have low maintenance in their first life, they do that in their second life, third life. The motor almost can’t wear out. Tesla batteries should go a long way. The seats will wear out before the motor ever does.

          • Peter Voight

            It’s something like that. Many ignore the influence a large battery has. Depth of discharge will be greater for the smaller battery. Say the Tesla is 70% discharged. The driver may want to top it up. Charger availability also influences the decision to charge. Overall, the state of charge will wander about an ‘average’ level that suits the driver. Fast charging will mean the Tesla driver will generally stop below 95%, because that bit is slow. Many smaller capacity EV’s will be left on the charger overnight to fully charge the battery, which aids range, but reduces cell life. The battery, car and charger are a system, and the relevant design choices are made in each case. There is no saying that the Bolt is inferior, or better, but another approach.

          • eveee

            Uumm. Maybe not. The 85kwhr and up batteries have unlimited warranties. The bigger the battery, the more fast charging slows down and seems like slow charging. Also, the bigger the battery, the more often it operates in the sweet spot from 20% to 80% depth of discharge (DoD). In theory, fast charging can lower lifetime and probably does. But Tesla batteries are holding up really well.
            http://cleantechnica.com/2015/05/18/battery-degradation-level-in-tesla-model-s-only-5-after-30000-miles/
            Maybe if you did nothing but ludicrous burn outs and fast charged every day…
            But who would do that?
            https://www.youtube.com/watch?v=LpaLgF1uLB8

      • Bob_Wallace

        Let’s assume the GM Bolt and Tesla Mod3 have the same range, features, build quality and approximately the same price.

        What do you think buyers will pick when one of the vehicles can be driving long distances and the other can’t?

        I think that, all other things being equal, people will purchase the Bolt only if the waiting list for the Mod3 is too long for them.

        • IfSlashWhen

          The Bolt is going to be a huge win, and yes there will be significant sales loss that Tesla could have capitalized on if they had been first. That doesn’t mean Tesla is dead though. If they have significant autonomous features in the 2017 Model 3, they can cut deep into the Bolt’s second year sales.

          • Bob_Wallace

            We’ll have to wait to see if you are right. But do remember that Tesla will be introducing the Model 3 in a few weeks. While potential EV purchasers won’t be able to buy a Tesla as soon as the Bolt they will likely know what each will offer.

            Would I wait a few months to get an EV that could be driven on long trips rather than getting a range limited EV sooner? Absolutely. I don’t want to have to own or rent a second car for when I might want to go more than 100 miles from home.

          • IfSlashWhen

            I agree, this is why the proprietary network Tesla has, is their ace in the hole (they can outfit the Model 3 with CCS as well as supercharger and instantly double the number of charge points available to Model 3 owners over the Bolt – brilliant).

          • Bob_Wallace

            GM could have used the Tesla system, they were not frozen out.

            GM is apparently battling with Nissan to be number two. That’s fine, we need as many EV choices as possible. But it would be great to see someone make a go at the first place slot.

          • Steve Grinwis

            This to me, is clearly not a “charging” system limitation. It’s something inherent to the car. We don’t know what it is. It could be LG’s batteries, or just them being to cautious… or trying to hit some sort of “Batteries must last 20 years” goal, or something. We just don’t know yet. It is baffling to me though.

          • Bob_Wallace

            I just found this online…

            “The MSRP of the Bolt is $37,500 before incentives, but the company didn’t reveal what the DC fast-charging option will cost.

            GM says that with the SAE Combo DC Fast Charge, the Chevy Bolt EV will be able to add 90 miles of range in about 30 minutes.”

            http://electrek.co/2016/01/11/gm-bolt-ev-battery-pack-fast-charging-full-specs/

            GM does not talk about it on their site…

            http://www.chevrolet.com/bolt-ev-electric-vehicle.html

          • Steve Grinwis

            This GM site claims 80% charge in “less than 45 minutes” but I think it’s talking about the concept car? Perhaps?

            http://www.gm.ca/gm/english/vehicles/chevrolet/2016-bolt/feature

            EDIT: And it’s weird because the Spark EV can do an 80% charge in 20 minutes:

            http://www.gm.ca/gm/english/vehicles/chevrolet/spark-ev/overview

          • Kyle Field

            The battery on the Bolt is almost 3X the capacity of the Spark…

          • Steve Grinwis

            That doesn’t matter. Go learn about C rate.

            http://batteryuniversity.com/learn/article/what_is_the_c_rate

          • Bob_Wallace

            Charger limitation? Smaller battery pack in the Spark, wouldn’t need to be as robust.

          • bwollsch

            The Spark EV has a 19kw battery, the Bolt a 60kw battery, so it takes longer to charge up that extra capacity. In addition, the Chargepoint Express 200 Chademo/CCS charger outputs at 50kw/hr, so you can see why it takes that long. The Tesla super chargers output at 135kw/hr, so they can charge a 70kw Model S 70 in less time.

            So the question is twofold, can the charging stations put out more electricity and can the car accept that higher charge rate without damaging the battery packs. If Tesla can do it, GM, Nissan, etal should be able to.

          • Steve Grinwis

            Kia has 100 kW chargers available. You need to read up on C rate, the correct way to discuss charge rates.

            http://batteryuniversity.com/learn/article/what_is_the_c_rate

          • eveee

            Which limits charging?

            C rate and charging. Get your hot dogs.

            http://cleantechnica.com/2016/02/14/battery-charging-explained-or-honey-who-shrunk-the-electrons/

            Others should be able to. That is the question. We don’t know for sure yet.

            On the other hand, a low C rate battery charged near its max C rate is no better than a high C rate battery charged near its max C rate. There are many variables. Temperature. State of charge, etc.

          • eveee

            You’re right. The battery doesn’t have to be a limitation if its NMC, but we don’t really know. Its a common technique to lower C to get higher energy capacity, so if LGChem did that to get a cheaper battery with more capacity…..
            We are just going to have to wait until more info is available about that. On the other hand we know SAE DCFC is limited to 50kw currently available units, and most are 25kw.
            As it stands, if you bought a Bolt today, you would have the slower charging regardless of the battery.

          • Steve Grinwis
          • eveee

            I tried to look for 100k chargers on the search map, but it doesn’t screen for kw.

          • Steve Grinwis

            I don’t think they are wide spread yet. I was merely pointing out that they are coming, and that SAE is capable of supercharger like quantities of juice.

          • eveee

            Yes and I hope they come soon.

          • bwollsch

            Tesla’s can already use CCS. They just have to buy the adapter from Tesla.

          • Tim

            Bob, whenever I go more than 100 miles from home, I end up driving back on another day. So perhaps we are talking about 200 miles from home. (More often than not.)

          • eveee

            Yes. I like to think of it in hours rather than miles. How long will you travel. More than an hour and half of high speed freeway is not usual for most people daily. There are multiple long distance modes people use, like the under 200 mile (3 hour) overnighter. For daytime travel, few will travel two hours and turn around and come back right away. That leaves time for charging on a day trip, even slowly. Little need to fast charge if there is a decent destination charge like a level 2. There is a break point somewhere above 175 miles one way. For me, the limitation of the Leaf is that there are some trips of 90 to 120 miles round trip that happen every so often that I cannot do. Like picking someone up from an airport. And that distance is short enough that one expects not to stay that long. Not enough time in some cases to charge enough for the return.
            IMO, even a 150 mile range vehicle would suffice if DCFC is widely available that can charge in 30 minutes. Not because of thirty minutes, but because if you travel 100 miles, you only need to charge less than 150 miles, and that will take proportionally less time.

          • Bob_Wallace

            That’s true for me as well. But I’m not driving coast to coast at 200 miles per day. ;o)

          • Steve Grinwis

            If vensonata is correct above, and the reason is that GM has traded fast charging ability for exceptional battery life, that may be an interesting gamble. If it becomes well known that GM battery packs last 500k miles, instead of Telsa 200k miles, that could play into consumer fears about battery packs wearing out quickly…

            It’s interesting. In the real world, how many drivers are really going to care about that extra half hour of charge, for long trips? I have no idea.

          • eveee

            Maybe its just me, but I don’t know if I believe GM just designed their pack to have 500k mile cycle life. Not unless they are excessively conservative. Now I am deeply curious why GM limits charge rate so much. I wonder if LGs pouch cells and chemistry have anything to do with it.
            It could be GM has less experience with the cells and so must be conservative until they can tell.
            It just doesn’t sound to me like something GM would normally do, designing a component to last half a million miles.
            I cannot believe GM is ignorant of how much their charing rate cripples the advantage of a large pack and long range. On the other hand, They seem to have made a different mistake twice. The early Volt protos had drag over Cd of 0.3. Later they trimmed that down, but its still not Tesla or Prius territory.
            The Bolt fails drag on two fronts. Frontal area and drag coefficient.

          • Steve Grinwis

            Despite the GM stigma, they do try and make things last forever. I’ve had two vehicles with over 500k kms. If GM can get the Toyota reputation for EV longevity, that could be worth a fortune to them… GM EV’s still on the road after 20 years…. Original battery pack..
            The advertising writes itself. Reliability is a huge concern for perspective buyers. Most people expect my electric car battery to wear out like a cheap cell phone still….

            Edit: the Volt pack is also excessively conservative

          • eveee

            IMO, the Volt pack is designed that way because an HEV has hundreds of charging cycles daily due to stop and go regen. The were real conservative about that. Thats good. Yes. I checked out Prius and noticed they last forever. Why? The engine doesn’t get as punished as an ICE. The battery always helps it from start. And the brakes last forever. The original NiMH battery is rugged.
            The Tesla suffers from Ludicrous mode. Heavy and performance means it eats tires. 🙂
            Really, if you can make a car with that much performance that doesn’t spend its life at the shop, thats pretty unusual.

          • theflew

            GM has the largest battery testing facility in the US. They probably have forgotten more than most know.

          • eveee

            Interesting. I don’t think biggest is necessarily best, but GM has been at this since the EV-1.

          • eveee

            You might want to think about GMs recent run ins with the law and lawsuits and injuries from “hot’ ignitions and the internal memos to cover up. VWs diesel gate scandal makes one think twice when you think about how good their laboratories are. A laboratory isn’t any good if the scientists are ignored or the management is dishonest.

          • Bob_Wallace

            If you were talking 100k vs. 250k then that might be a consideration for buyers. But 200k vs. 500k? I doubt there’s much there.

            At 200k the car should still have 80% of new range, 160+ miles. Most people aren’t going to buy a car with 200k miles on it for long distance driving but for economical commuting.

          • Steve Grinwis

            Because the same type of fear that drives people into large SUVs and minivans for their family of 3, will drive people into vehicles that seem like they will last forever. Even though people should rationally know that they are unlikely to keep a car for more than 8 years. They’ll say, but, what if I needed to drive that long distance in the winter, that one time…. My car needs to fit my needs!

            The first round of widespread battery replacements in Leafs will drive a lot of irrational fear, despite being completely expected and predictable.

        • Even if the Model 3 and Bolt had similar specs (Model 3 likely to be better), the Model 3 would sell many more simply because it will likely look like a sedan. “Eurohatch” styled vehicles sell in relatively low volumes in the U.S. simply based on design tastes. Honda Fit 50k-ish sales per year, Honda Civic, 300k to 400k-ish sales per year.

      • eveee

        Yep. GM is still on the PHEV bandwagon, a losing proposition in the long run. They have announced willingness to share their PHEV tech and they seem to be trying to spread PHEV to there rest of their lineup. We are going to see an interesting shuffle as manufacturers scramble to do something about their increasingly anachronistic ICE lineup while trying to figure out what to do about sinking gas prices.
        This whipsaw is inducing some real churn for them.

        • Steve Grinwis

          Honestly? PHEV is a good way to go right now, as much as we’d all love EVs.

          You can talk anyone into a PHEV if it’s cheap enough. “Do almost all your driving on gas, but still drive across the country like you did before if you want”. Easy sell. Once they see how long their 60+ km range actually takes them in a day, a pure EV becomes an easier sell.

          • eveee

            If a PHEV and an EV cost the same, and the range is 200 miles, the EV comes out ahead on operation and maintenance. The tipping point has just gotten closer.

          • Steve Grinwis

            Just because it costs the same doesn’t mean people will be willing to change, sadlt.

          • eveee

            Aint it the truth. People spend lots of money on useless gadgets and toys. Performance equipment that does little or nothing. Just put the word sport on anything and it sells. Or bacon flavored. LOL.

          • Joe Viocoe

            “Do almost all your driving on gas”… you mean battery, right?

          • Steve Grinwis

            Yup! Sorry!

          • eveee

            Its a good idea right now, because some people will may not go the EV route.

          • ROBwithaB

            Exactly.
            PHEV: The “gateway drug” to full blown electric addiction.

  • Thanks for the analysis – seems spot on to me. We do know the claimed Cd: The upcoming Chevy Bolt EV has a claimed Cd of 0.312, and a frontal area of 25.8 sq ft, for a CdA of 8.05 sq ft.

    http://www.popularmechanics.com/cars/hybrid-electric/g2429/12-things-to-know-about-chevrolets-30000-bolt-ev/

    • IfSlashWhen

      That is probably for the prototype. Going from .312 to .285 is finishing details (that likely won’t be there on the prototype).. I’d expect around .285 for production.

      • If we could get side video mirrors, the Cd AND the frontal area would be reduced.

        • eveee

          That would be great. Now all we have to do is convince legislators in 50 states to separately and simultaneously do that. Easy.

          • I think they would only have to be approved at the federal level.

            If we cannot get side video mirrors approved, then I don’t think full autonomous driving has a chance for ~10X longer.

          • eveee

            The feds have been pushing removing truck side mirrors for a while. Tesla was pushing it on cars, too. Did you notice that the Bolt has a rear view electronic camera, too? If all the companies pushed it to congress it would happen. As it it is, nothing is happening.

        • Arthur Burnside

          Get real – if side mirrors are important, electric cars are in bad sghape. It’s all about the cost of the battery and its size/weight and recharge speed. Nothing else matters very much when trying to sell an EV. Even claims of being “clean” are phoney – rthey are no cleaner than the electricity they use. And what if the simple minded greenies should succeed in dramatically lowering the atmospheris CO2? A probably Ice Age and mass starvation, 10,000 times more deadly than a world a few degrees warmer. Let’s save out planet from these would be saviors.

    • eveee

      Thanks. Ugggh. Worse than I expected. I was hoping for 0.28. With its large frontal area, its almost a cinch it will have trouble with 200 miles at highway speeds.

    • MorinMoss

      Isn’t Tesla aiming for sub 0.20 Cd with Model 3?
      What would that look like?

      • Yes – it will look sleek and gorgeous!

        The Model S is Cd 0.24 and that looks great, right?

        • MorinMoss

          Sub 0.20 is hard to achieve. Guess we’ll find out in about 6 weeks.

          • Yes, but it is possible: the EV1 and XL1 0.20 or below.

          • MorinMoss

            Both had very unconventional looks; if Tesla goes that far off the norm, it may not have the broad appeal that’s needed for them to reach hundreds of thousands in sales.

          • Beauty is as beauty does.

            I think the XL1 is gorgeous.

          • Peter Voight

            Some manufacturers go out of there way to produce cars that stand out from the others. That way, drivers of EV’s can advertise whatever is fashionably related to EV’s.
            Being ‘green’, up to date, etc.

            No different from wearing clothing, badges or wrist bands for the same reason.

          • Low drag is much more than a style – it is a critical function. Low drag means longer range on a smaller battery, and that means lower cost and/or more range.

          • Peter Voight

            The i3 is the most efficient EV, but does not look to be low drag. That was not my point, though.

            There may be a market for EV’s adopting the shape of current gasoline models. The Leaf and i3 stand out, as ‘different’. It’s a way of advertising that the driver is ‘different’, and not easily persuaded by the usual image, but considers the environment or function to be more important. Both methods may sell cars,

          • The i3 also has the lowest rolling resistance tires currently available, so that is how it achieves its efficiency, and it is lower aero drag than you might think.

            You are partially conflating aerodynamic drag with styling. The Model S and the 3rd gen Prius are tied for the lowest aero drag for cars sold in the US. The Model S is bigger, but it has a lower Cd. It also looks a lot better than the Prius, so that is my point.

          • Peter Voight

            Of course, but looks are subjective. Buyers look for bullet point numbers, such as Cd.

            My point was that appearance can be used one way or the other.
            Since you mentioned tires, the second chart shows ‘Wh/mile v
            force, not power. Aerodynamic power would be cubic with speed, which it isn’t. The tire data assumes the simple and unrealistic tire model, where rolling resistance is constant, so force is constant. Power in that case rises with velocity, so the x-axis is certainly force.
            But, power output influences battery and motor efficiency. The drive chain, tire and aerodynamic loss, are ‘imagineered’ from Tesla’s chart.

          • Smart ED is much lighter than the i3… much smaller too, but that’s great for me!

  • Hazel

    Looks an awful lot like the Ford C-Max, from the short overall length to the high ceiling and tall windshield, right down to the small triangle windows in front of the rear-view mirrors. Should make for a similarly spacious cab with excellent visibility on a small footprint. I like it.

    Also, excellent review, I appreciate the technical detail!

    • IfSlashWhen

      Yes, excellent review.

      • Lorirpahl1

        ;c110Work At Home….Special Report….Earn 18k+ per monthfew days ago new McLaren. F1 bought after earning 18,512$,,,this was my previous month’s paycheck ,and-a little over, 17k$ Last month ..3-5 h/r of work a days ..with extra open doors & weekly. paychecks.. it’s realy the easiest work I have ever Do.. I Joined This 7 months ago and now making over 87$, p/h.Learn. More right Here;c110➤➤➤➤➤ http://www.nationalemployments.com.­nu .❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:❦2:::::;c110…

Back to Top ↑